Alkylated hydroxyaryl compounds are used in making phosphite compounds through a reaction with PCl3, as described in U.S. application Ser. No. 11/787,531, entitled “LIQUID PHOSPHITE BLENDS AS STABILIZERS,” the entirety of which is incorporated herein by reference. Such organic phosphites are used as secondary antioxidants for polyolefins and elastomers.
Conventionally, alkylated hydroxyaryls have been synthesized in the reaction of an olefin with a hydroxyaryl, optionally in the presence of a suitable catalyst. The alkylation of hydroxyaryls with substantially pure olefins is a widely known method. The cracking of a hydrocarbon feed stream, such as naphtha, by fluid catalytic cracking or steam cracking, and subsequent isolation processing of one fraction of the hydrocarbon feed stream allows production of the purified lower olefins, such as C2-C5 olefins, e.g., ethylene, propylene, butylene, and amylene. Isomers of higher olefins obtained from cracking rapidly increase in number, making similar isolation unfeasible. The process steps for separating C2-C5 olefins from the feed stream increases costs and reduces total production time.
C4 fractions generally contain a mixture of 1,3-butadiene, isobutene, 1-butene, trans-2-butene, cis-2-butene, butane, isobutane, vinylacetylene, ethylacetylene, and 1,2-butadiene. To obtain pure olefin isomers from a C4 fraction various processing steps are often required. For example, 1,3-butadiene is removed by hydrogenation, leaving a complex hydrocarbon stream comprising isobutene, n-butene, and butane as the major components. Separation of the isobutene by distillation of the complex hydrocarbon stream, however, is difficult due to the close boiling points of the components. Isobutene may be removed from the raffinate by shape-selective isolation or by chemical reaction. Such chemical reactions include hydration, addition of methanol to isobutene over an acid ion exchange resins, and oligomerization or polymerization of isobutene. The first two chemical reactions are reversible and are used when obtaining a substantially purified isobutene. The addition of methanol to isobutene over an acid ion exchange resin forms methyl-t-butyl-ether (MTBE). Health and environmental concerns exist, however, with MTBE, especially with respect to minimizing groundwater contamination. After these chemical reactions, the remaining components of the C4 complex hydrocarbon stream may be separated by extraction distillation into different substantially purified olefins and saturates.
U.S. Pat. No. 4,914,246 describes a composition comprising monoalkylphenols prepared by selectively alkylating the olefin component of thermally cracked sulfur-containing petroleum distillate derived from residua. The olefin component is a linear C5-C12 olefin.
U.S. Pat. No. 4,568,778 describes a process for producing t-amylphenols by reacting isoamylene with phenols in the presence of an inorganic solid acid catalyst or an acidic ion exchange resin catalyst. The isoamylene is obtained by hydrogenation of isoprene-extracted C5 fraction.
Dimerization of ethylene and disproportionation of propene are other commercially available synthesis routes to obtain olefins, especially butene. However, dimerization of ethylene primarily produces 1-butene and 2-butene as major components.
In view of the conventional processes, the need exists for an efficient source of olefins to be utilized in the production of alkylated hydroxyaryls, and in particular in the production of alkylated hydroxyaryls that may be used, for example, in the manufacture of alkylaryl phosphites, which may be used as secondary antioxidants for polyolefins and elastomers.